ZMONSTER!

iTrader: (9)

for now definetly. but hell I already want a bigger cam! just need heads that will allow for it

z28poweredlt1

iTrader: (1)

Why do you think 241 heads are going to allow for it? You're going to lose compression and intake velocity. Not to mention if you go with a bigger runner, and less compression you're going to be losing mid range hp/tq.

I may be wrong on all this, but unless you're getting heads with a runner thats a good amount bigger, you're going to be waisting time/money on it.

ZMONSTER!

iTrader: (9)

Well I cant run a bigger cam with my 5.3's as safely as I would like because mr. valve would meet mr. piston. As 241 and the 5.3's are both stock castings and recognizing how many cam only LS1's there are out there I think a set of well ported 241's would go well with a 230 ish cam. Id also have them milled, but not to the extent I had my 5.3's.

z28poweredlt1

iTrader: (1)

What head gasket are you running right now?

All in all its up to you. I'm just saying thats a lot of work, that might have been avoided with a little homework.

Is it worth the cost of new heads vs flycutting?

Even then your DCR might be to high though. Can we get any of our senior members in here to chime on this? How big of a cam can he use with the stock GM MLS gasket on 59cc 5.3's?

I'm running an MS3 237/242 .603/.609, with no clearance issues. I made 460/414 to the tires on stage 1 243 heads, but after one broke I decided to go with the 5.3 heads for the design and compression. I'll let you know if I make the same rwhp, but I'm assuming the tq will go up.

Hope we can help in someway lol.

ZMONSTER!

iTrader: (9)

Agreed I should have done more homework when the option of having my heads milled was given. It was actually a last minute thing and I should have opted to leave them alone, so I would have some room to grow.
Ive actually been in contact with predator z quite frequently about this. Ill just say hes been a huge help and my setup would have been much more of a headache without his input. I wish I had contacted him earlier in my build.
As far as the cost of new heads vs, flycutting well new heads wont cost me anything other than a port and valve job, as I still have my 241 heads. Flycutting is something id like to avoid alltogether, although I will search on this issue.
How much are your 5.3's milled?

z28poweredlt1

iTrader: (1)

I'm not milling them at all because of the cam I'm using, so 62cc I believe. I almost bought a set of used heads that where 59cc, but TSP helped me out with replacement heads for my broken PRC ls6 heads. So I would have had to flycut. Which doesn't seem to be an issue so long as you're not running big boost or a big shot of nitros.

+1 for Predator-z, he was the senior member I was referring too. He knows basically anything and everything about compression. Did you guys figure out if there is any possible way you can go bigger without flycutting? (GM gaskets etc?)

ZMONSTER!

iTrader: (9)

there dosent seem to be, i could possibly go with a 228 size cam but that would be about it.
Ive been looking into flycutting here...very interesting. Id be able to keep a higher CR and have a bigger cam that could make better use of it. Hmmm, Im gonna have to look around my area for competent shops that could flycut.
Either way whatever I decide to do will be around a year away, so I have time for homework. I started this thread because I wanted to know how far you could take a set of 241's, and its still an option to me.

fauslpss

iTrader: (6)

Well the heads I have aren't hogged out that is why they make good TQ if you have a head like a TSP or patriot, not trying to bash, the ports are big 225-230cc air velocity is low killing TQ.

The guy who ported these heads tested them on his car, 346ci, made 460whp and 410tq with a good TQ curve that's through a S60. He had streetsweeper from New Era, ARH, and 78mm fast.

If your budget minded then find a good porter and port the 241's. They do have limitations but like you said you already have them and you won't spend much. I'm very impressed with them and so is the guy in NY.

These were the 1st LSX heads that I bought so I didn't want to spend a lot. Next ones are going to be ETP's or AFR's.

Eric

ZMONSTER!

iTrader: (9)

wow what are the cam specs on that motor?
Very impressive! Im pretty happy with my heads, but think this is interesting. Thanks for posting fauslpss!

fauslpss

iTrader: (6)

The cam specs for his motor were 236-240 .630-.612 with a 112 lsa.

Eric

fauslpss

iTrader: (6)

From what I know 241's are 205cc not a big runner. And their only get as big as you want them to get. Its not always runner volume that makes N/A power its deals with velocity as well. It gives you a better cylinder fill.

You can deck any head to increase compression or thinner head gaskets. The 241's that I have are 59cc combustion.

Eric

fauslpss

iTrader: (6)

Well it shouldn't be much longer till I get my heads and cam in hand and get some pics up. Then its up to me to install and get it tuned at Norris.

Never got it flowed so well let the #'s speak. I did get a cam only and a head and cam dyno from the guy that sold me the heads. 415hp 389tq cam only and 460hp 410tq with the heads. So that ought to let you know that a moderate 241 casting can give you. The guy in NY said the VJ wasn't very good but he exspected that. So with A good VJ it would be even more.

Eric

Jason 98 TA

iTrader: (4)

This statement is definately made by someone with very little actual dyno testing. I've engine dyno tested many, many different head combos on LS based engines & having a little bit of runner size is not neccessarily a bad thing. I'd be more than happy to share some dyno comparisons with you guys on small runner 205cc heads, PRC 220cc 5.3l heads & the new PRC 215 aftermarket casting. For the money the PRC 5.3l stage 2.5 heads did very well next to the bigger money aftermarket castings....

fauslpss

iTrader: (6)

A big runner on a 346ci will have low velocity in the low to mid range killing the potential for a good TQ number.

We are all looking forward to seeing the new casting you are making, what 205 are you referring to AFR's?

Eric

studderin

iTrader: (28)

eric thouse heads sound bad ***

any flow numbers with that stock valvejob yet?

fauslpss

iTrader: (6)

I have to say it was a good investment on my part, I sent them to Bret at BRE he said they look better then any TSP or patriot head. The only place it was really lacking was the VJ.

I'll be getting them on thurs first time I'll get to see them since I bought them. lol I was going to get them flowed but bret said he didnt need to know so Im just going to see the hp numbers. They made close to 45 improvement over your cam only. So im happy with that. I'll keep you updated on the set up once I get everything together.

Did you flycut Im debating whether or not to use .40 head gaskets and if its worth the HP?

Eric

LS1Formulation

iTrader: (13)

I have a pair of CNC ported 241's and although my car hasn't been dyno tuned, I've ran 12.43@116.6 and 12.47@117.1 with 2.0 60 ft times. I'm planning on swapping the heads out for PRC 5.3's this winter, so I'll see exactly what gains they give me. The heads I have now were on my friends car and he ran 11.17@121 with a 228/236 cam in an A4, so you can see the potential they have. I just think for what I am doing, 5.3's will make a lot more midrange torque. My 241's will be for sale for a lot cheaper than you could have yours ported for, by the way. They're set up with Ferrea valves and Patriot Golds. Shoot me a PM if you're interested.

ZMONSTER!

iTrader: (9)

/\ damn good time, 11.17!
I really need to get mine to the track

Black FormulaLs1

iTrader: (10)

great thread..i will have to contact predator Z as well evidently!! i am running forged mahle pistons and rods and the pistons already have valve reliefs cut into them..my current cam is a lunati 234.236. 544.545 @ 112 LSA and i am running hogged out 241's with 2.02 and 1.90 valves * ferra* and patriot golds as well..LS6 intake and TB also..i will have to contact the guy i bought my heads from and see if he will send me the flow sheet but the heads have only been milled .0006 to true deck them..right now only a basic street tune as the engine was built fresh, new ram clutch, stage 2 Tick performance T56 and a new 12 bolt ..gotta have break in time...soon a WOT tune and #'s!!


i have pics of them in my myspace under rachell... www.myspace.com/stangslayer99

fauslpss

iTrader: (6)

Ls1forulation did you granny it off the line? I would figure you would at least have made it in the 11's or 12 O's. I think a cam would be the better route if you want to pic up mid range, and less expensive.